JPH057259U - Golf club - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to improve the durability of the golf club by strengthening the strength of the head neck top portion in a golf club in which a metal club head is mounted on an FRP shaft. [Structure] The tip of the FRP shaft 2 is mounted in the hole 4 of the head neck portion 3 of the club head 1,
When the FRP shaft 2 is mounted, the FRP shaft 2 is fixed to the neck portion 3 of the club head 1 via the FRP adhesive layer 5.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a golf club having a metal head mounted on a fiber reinforced plastic shaft.

[0002]

[Prior Art]

 At present, golf club shafts (hereinafter referred to as shafts) include metal shafts and fiber reinforced plastic (hereinafter referred to as FRP) shafts.

On the other hand, club heads mounted on these shafts are roughly classified into wooden (persimmon tree etc.) heads, metal heads, FRP heads, or a combination thereof, and the shaft and the head are joined together. Generally, a synthetic resin adhesive such as an acrylic resin is generally used as a single adhesive.

When the metal head is adhered, a method of chamfering the inner surface of the top of the head neck is usually used in order to reduce stress concentration at the top of the head neck.

[0005]

[Problems to be solved by the device]

 By the way, since the adhesion clearance between the shaft and the head is about 0.1 mm in diameter, the head chamfering lower edge portion at the top of the neck may come into contact with the shaft for adhesion. In this case, if a shaft made of FRP, especially a shaft with low bending strength and impact strength near the neck due to the base material composition and wall thickness, is installed, the impact stress at the time of impact exceeds the allowable stress of the shaft and the shaft is damaged. It is more likely to be linked to, which is a practical problem.

Further, even if the shaft is adhered so as not to come into contact with the edge portion, since the adhesive layer is a single adhesive, and the adhesive layer itself is thin and low in strength, the adhesive layer itself cannot withstand the stress. Will be broken.

On the other hand, it has been pointed out that when the adhesive layer is thickened, the adhesive force is lowered and the head is easily displaced or the head is easily pulled out.

The present invention has been made in view of these problems, and an object of the present invention is to reduce the shaft breakage rate at the top of the head neck and improve the durability of a golf club. To provide.

[0009]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention is a golf club in which a FRP shaft is mounted in a hole at the top of a neck of a metal head and integrated through an adhesive layer, wherein the adhesive layer is made of FRP. It is characterized by

The FRP adhesive layer is selected from reinforcing fibers such as glass fibers and carbon fibers, and synthetic resins such as acrylic resin and epoxy resin.

Further, the thicker the adhesive layer is, the more advantageous it is in terms of strength. However, if the diameter of the shaft is made smaller to cope with it, the strength of the shaft itself is lowered. However, the head hole diameter is also set in consideration of the head neck strength.

Further, as the reinforcing fiber used in the FRP adhesive layer, glass fiber is suitable in terms of the degree of freedom of fiber form, workability, impregnation property, and the like, and the synthetic resin is excellent in impact resistance and peel strength. A thermosetting two-component acrylic resin, which has good adhesive workability and allows easy replacement of the shaft and head, is suitable.

As a method for forming the FRP adhesive layer described above, a synthetic resin used as an adhesive is mixed with chopped strands having a short fiber length in advance, and a hardening agent is added to the shaft to form a shaft. There is a method of applying and pouring it into the head hole to bond and solidify it, and a method of previously winding an adhesive strand or a woven or non-woven fabric around the shaft, and then impregnating or pouring the resin so that it adheres and solidifies.

The former is liable to be misaligned during insertion and bonding of the shaft. Therefore, as in the latter, there is a method in which the adhesive layer can be surely secured by winding the fiber before bonding and the head chamfered edge part and the shaft do not contact Are suitable. A method of winding and adhering fibers impregnated with resin in advance can also be used.

[0015]

[Action]

 As is clear from the above configuration, when the FRP adhesive layer is used for joining between the FRP shaft and the neck top of the club head, as shown in Table 1, as compared with the conventional acrylic resin adhesive layer, The strength of the neck top is significantly enhanced.

[0016]

【Example】

 Hereinafter, embodiments of the golf club according to the present invention will be described in detail with reference to the accompanying drawings. In FIG. 1, this golf club is composed of a metal club head 1 and a FRP shaft 2 and has a hole 4 of φ8.6 mm formed at the top of a neck portion 3 of the club head 1. The tip of the FRP shaft 2 is mounted in the hole 4 via the FRP adhesive layer 5.

The FRP shaft 2 is formed by impregnating a carbon fiber epoxy resin, molding the surface, and then grinding the surface to make the outer diameter of the neck portion (portion to be inserted into the hole 4) φ8.4 mm. After that, the adhesive surface is roughened with a polishing cloth (roughness # 80), and glass fiber strands (manufactured by Fuji Fiber Glass Co., Ltd., 150TEX product) are wound in the circumferential direction.

Next, an adhesive Versa Rock (acrylic resin, trade name of Lord Far East Incorporated) is blended, and the glass fiber strands are quickly wound around the adhesive surface of the shaft 2. The entire surface is coated and it is injected into the hole 4 of the head 1. Immediately thereafter, the FRP shaft 2 is inserted into the hole 4 of the head 1, the protruding fibers and resin are removed, and the mixture is cured at room temperature to be adhesively solidified to obtain the golf club according to the present invention.

Then, the golf club of the present invention thus manufactured and the golf club using the conventional acrylic adhesive layer were evaluated for durability by robot hitting three samples each, and the results are shown in Table 1. Got

[0020]

[Table 1] As is clear from Table 1, it can be easily understood that the strength at the top of the neck is significantly enhanced.

[0021]

[Effect of the device]

 As described above, the golf club according to the present invention comprises the metal club head and the FRP shaft, and the FRP adhesive layer is used to join them to reinforce the strength of the top of the neck significantly. It has the effect of significantly improving durability.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a golf club according to the present invention.

[Explanation of symbols]

 1 ... Club head 2 ... FRP shaft 3 ... Head neck part 4 ... Hole 5 ... FRP adhesive layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshiyasu Ishikawa 1150 Gozamiya, Shimodate, Ibaraki Prefecture Gotomiya Plant, Hitachi Chemical Co., Ltd.

Claims (1)

[Claims for utility model registration] [Claim 1] FRP is placed in the hole at the top of the neck of the metal head.
A golf club in which a shaft made of steel is attached and which is integrated via an adhesive layer, wherein the adhesive layer is made of FRP.